For example, a display device including a liquid crystal panel may have a polarizing film at an outermost surface. A surface of the polarizing film may be, for example, formed of a triacetylcellulose (TAC) film. However, since the TAC is susceptible to being scratched, a hard coat layer may be arranged on the TAC so as to prevent the TAC from being scratched.
Here, as an ingredient for preventing scratches, metal oxide particles are generally contained in the hard coat layer. Also, in order to suppress charging of a polarizing film, a conducting material may be added to the metal oxide particles.
Also, it is preferable that the polarizing film has a capability to suppress reflection. In this regard, a low refractive layer for disturbing reflection of light incident from the outside may be disposed on the hard coat layer. Here, reflectance may be decreased when a binder formed of an incompatible resin is included in the low refractive layer such that a convex-concave structure is formed on a surface of the low refractive layer. Also, additives may be added to the low refractive layer to impart an antifouling property and a slippery property to the low refractive layer.
Patent Document 1 discloses an anti-reflection film. The anti-reflection film is directly formed on at least one surface of a transparent substrate film or with another layer therebetween, thereby forming an anti-reflection layer. The anti-reflection layer satisfies a refractive index: ND20≤1.49 and is formed of at least two low refractive index materials.
Also, Patent Document 2 discloses a curable resin composition. A multifunctional silane compound including a multifunctional (meth)acrylate is chemically bonded to a surface hydroxyl group of silica fine particles. An organic-inorganic hybrid hard coating solution including the organic-inorganic silica particles and an antistatic coating solution are mixed. The antistatic coating solution includes conductive metal oxide fine particles having a multifunctional (meth)acrylate chemically bonded to a surface thereof. Also, due to a self-organizing property of the two coating solutions, an antistatic property and an anti-glare property may both be realized in a single layer. Further, a phase-stabilizing agent is added to the antistatic anti-glare coating solution to control the self-organizing property of the antistatic anti-glare layer. Also, the convex-concave structure of the antistatic anti-glare layer is controlled to have a nano-scale size so as to lower a refractive index, and thus, a low-reflection function may be imparted to the layer.
Also, Patent Document 3 discloses an anti-reflection film having a sea-island structure formed by a phase not having silica particles and a phase having silica particles.
Also, Patent Document 4 discloses a hard coat film which has a hard coat layer disposed on a substrate. The hard coat layer includes an ionizing radiation-curable resin that has a multifunctional monomer having two or more (meth)acryloyl groups in one molecule as a main ingredient. An amount of the ionizing radiation-curable resin is in a range of 90 parts to 10 parts by weight. Also, the hard coat layer includes the conducting material at an amount in a range of 10 parts to 90 parts by weight. The conducting material in the hard coat layer is unevenly distributed with a greater concentration toward an upper surface of the hard coat layer. Also, the substrate is a triacetylcellulose film.
Also, in Patent Document 5, a hard coat film is disclosed having a hard coat layer. The hard coat layer includes an ionizing radiation-curable resin stacked on at least one surface of a substrate of the hard coat layer. The hard coat layer has 90 parts to 30 parts by weight of the ionizing radiation-curable resin and 10 parts to 70 parts by weight of a conducting material as main ingredients. The 90 parts to 30 parts by weight of the ionizing radiation-curable resin includes a multifunctional monomer containing two or more (meth)acryloyl groups in one molecule as a main ingredient. Also, a refractive index difference between the substrate and the hard coat layer is in a range of 0.01 to 0.1. The hard coat layer is formed by using a coating solution including at least one solvent that dissolves or swells the substrate and a solvent which stably disperses a conducting material.
Also, in Patent Document 6, a stack that includes a hard coat layer and an anti-reflection layer including an inorganic oxide stacked in the stated order. The hard coat layer includes an ionizing radiation-curable resin compound having an ionizing radiation-curable resin and a conducting material as main ingredients. The ionizing radiation-curable resin includes a multifunctional monomer containing two or more (meth)acryloyl groups in one molecule on at least one surface of a substrate as a main ingredient. The ionizing radiation-curable resin includes a multifunctional monomer that contains at least one —OH group in one molecule. In one embodiment, the ionizing radiation-curable resin has a refractive index difference between the substrate and the hard coat layer in a range of 0.01 to 0.1. In one embodiment, the hard coat layer is formed by using a coating solution including a solvent of at least one type that dissolves or swells the substrate and a solvent which stably disperses a conducting material.